A conventional powered dispensing gun as disclosed in U.S. Pat. No. 8,740,021 B2 includes four cartridges of different styles and sizes detachably connected to a tool housing by a quick-change assembly for accommodating two different packing styles of dispensing material, i.e., a cardboard tube-style and a sausage pack. Each of the cartridges has an individual rack and a plunger mounted therein, which are required to be replaced therewith upon change of the cartridges, thereby resulting in inconvenience during use and carrying.
Referring to FIG. 1, another conventional power operated dispensing tool includes a main housing 1 with a cartridge housing 101 attached to the front end thereof, a micro switch 2 disposed at the rear end of the housing 1, and a rod 3 driven by a motor (not shown). The rod 3 has a rack 301 and a handle 302 disposed at the rear end of the rack 301. Two different sizes and configurations of plungers 303, 304 are removably disposed at the front end of the rack 301 to be used with a cardboard tube-style cartridge and a sausage pack cartridge, respectively. The rod 3 is moved forwardly until the handle 302 contacts the micro switch 2 to stop the motor, where the plunger 303 stays in the cartridge housing 101. Hence, once replacement of the plunger is required, it is necessary to operate a hand tool 4 to get access to the cartridge housing 101 for removing the plunger 303 from the rod 3 and then installing another plunger 304, which results in quite an inconvenience during the replacement.